After shaking hands and exchanging greetings, the president-elect got down to work.

Not at Independence Hall, where a little more than an hour later he was to meet with 48 governors begging for handouts, but at the Philadelphia Sports Club in Franklintown.

There, Barack Obama did 45 minutes of intense cardio training and left behind a starstruck gaggle of club members and staff - one of whom grabbed a sweat-soaked souvenir.

About 30 gym-goers - all frisked by agents on their way into the club - applauded as Obama entered at 8 a.m., said club manager Dion Linderman.

Dressed in plain gray sweats and a blue ball cap, Obama jogged for 30 minutes on one of the club's high-tech treadmills and put in 15 more on an elliptical machine while plugged into an iPod.

No one dared interfere with the future commander-in-chief's workout. Club members respected Obama's privacy, Linderman said, though a jogger at an adjacent treadmill tried to keep up with his brisk pace.

"Barack was just too fast for him," said assistant manager Will Nelson, who bears a striking resemblance to Obama.

It was Obama's third visit to the club at Rodin Place next to Whole Foods Market.

"Last time, he did weights with a little bit of cardio," said Nelson. "This time it was a cardio workout all the way."

Also different this time: the size of his entourage. Obama brought only five Secret Service agents with him when he visited the gym in April and August. Yesterday, the security detail was up to 30.

After a 45-minute routine, Obama posed for a picture with the staff and tossed his towel to Nelson.

Nelson instinctively went to drop it in the towel bin. But he checked himself when he realized he might have the equivalent of a future holy relic on his hands.

"I'm going to put it in a plastic bag, and I'm never going to wash it," Nelson said, tongue only partly in cheek.

"I suppose I could cut it up, sell it on eBay, just like pieces of the cross," he said, somewhat slyly. "But that wouldn't be right, would it?"